Fastening apparatus, system, and method

Abstract

A downhole tool includes a body having a rounded or cylindrical surface, at least one relieved space in the rounded or cylindrical surface, and a protuberance within the relieved space. The downhole tool also has a generally cylindrical retaining ring that surrounds a portion of the body. One or more crimple detents are formed in the retaining ring, each crimple detent comprising a portion of the retaining ring that has been deformed radially inward into an underlying portion of the relieved space such that the deformed material of the retaining ring contacts and deforms an underlying portion of the protuberance in the relieved space, thereby joining the retaining ring to the body.

What is claimed is: 
     
       1. A downhole tool, comprising:
 a body having a rounded or cylindrical surface, at least one relieved space in the rounded or cylindrical surface, and a protuberance within the at least one relieved space; 
 a retaining device; 
 one or more crimples, each crimple including a portion of the material of the retaining device that extends inward into a corresponding portion of the relieved space of the body and which deforms the protuberance within the corresponding portion of the relieved space. 
 
     
     
       2. The downhole tool of  claim 1 , wherein the protuberance comprises a circular ring of material that extends radially outward from the body within the relieved space. 
     
     
       3. The downhole tool of  claim 1 , wherein the one or more crimples each comprise a deformation in a wall of the retaining device that presses against an underlying deformed portion of the protuberance in the relieved space to prevent the retaining device from moving with respect to the body. 
     
     
       4. The downhole tool of  claim 1 , further comprising a plurality of pads having tabs, wherein the retaining device functions to retain at least a portion of the pads adjacent the body. 
     
     
       5. The downhole tool of  claim 1 , wherein the protuberance has two sides which meet at an angle of between 40° and 135°. 
     
     
       6. The downhole tool of  claim 1 , wherein sides of the relieved space have an angle between the sides in a range of 40° to 120°. 
     
     
       7. A method for securing a first body to a second body, comprising:
 inserting at least a portion of the first body into the second body, wherein the first body has a rounded or cylindrical surface, a relieved space in the rounded or cylindrical surface, and a protuberance within the relieved space; and 
 deforming a portion of the second body such that material of the second body extends inwardly into an underlying portion of the relieved space of the first body and such that the inwardly extending material of the second body deforms an underlying portion of the protuberance on the first body to affix the first body to the second body. 
 
     
     
       8. The method of  claim 7 , wherein the protuberance comprises a circular ring of material that extends radially outward from the first body. 
     
     
       9. The method of  claim 7 , wherein the protuberance has two sides which meet at an angle of between 40° and 135°. 
     
     
       10. The method of  claim 7 , wherein sides of the relieved space have an angle between the sides in a range of 40° to 120°. 
     
     
       11. The method of  claim 7 , wherein deforming a portion of the second body comprises pressing a die into an external surface of the second body. 
     
     
       12. The method of  claim 11 , wherein deforming a portion of the second body further comprises supporting the second body in a block prior to pressing the die into the external surface of the second body. 
     
     
       13. The method of  claim 7 , wherein the second body comprises a generally cylindrical outer surface having a circular groove therein, and wherein deforming a portion of the second body comprises pressing a die with a concave shaped blade into a portion of the circular groove.